Hydrocarbon resin, method for preparing hydrocarbon resin, and adhesive composition

ABSTRACT

This invention relates to a hydrogenated hydrocarbon resin and a method of preparing the same, wherein the preparation process is simplified, material supply problems can be solved, and the hydrogenated hydrocarbon resin can be prepared using a catalyst, which is inexpensive, has a low odor and is easy to handle, thereby realizing a yield and a preparation process that enable real-world application thereof. The hydrogenated hydrocarbon resin prepared by the method of the invention has excellent compatibility and a low specific viscosity, and can thus be efficiently used as a tackifier or an adhesive in a variety of fields.

TECHNICAL FIELD

The present invention relates to a hydrocarbon resin, a method ofpreparing the same, and an adhesive.

BACKGROUND ART

A hydrocarbon resin is a representative tackifier and is mainly used asa material that imparts tackiness or adhesiveness to adhesive tape orproducts such as paint, ink, rubber, tires, etc. It is a thermoplasticresin in a liquid or solid phase at room temperature and may be providedin various forms ranging from a transparent semi-fluid liquid to a lightyellow or water white solid.

A hydrocarbon resin, especially a hydrogenated hydrocarbon resin, is athermoplastic resin prepared from a high-grade unsaturated hydrocarboncontained in thermal pyrolysis oil such as naphtha or the like inpetrochemical plants, and has excellent resistance to heat andultraviolet (UV) rays and may be adhesive, and thus may be variouslyutilized in medical supplies, woodworking articles and sanitaryarticles.

Although the number of products using hydrocarbon resin is increasingevery year, the production of C5 and C9 oil fractions, currently usefulas the main materials for hydrocarbon resin, is decreasing, and theshortage of material for hydrocarbon resin may become severe.

Meanwhile, in the case of a hydrogenated hydrocarbon resin, it isdifficult to completely remove unreacted materials, a solvent and alow-molecular-weight oligomer during the preparation thereof, and thus,upon the manufacture of sanitary products such as diapers and the like,which involves spraying an adhesive at a high temperature, the odor ofthe hydrocarbon resin itself is generated, and may be released when thefinal product thereof is unpacked. Furthermore, the hydrogenatedhydrocarbon resin may generate an offensive odor peculiar thereto whenmelted at a high temperature, thus adversely affecting workingenvironments. Moreover, when it is applied to sanitary products,limitations are imposed on satisfying the needs of consumers who requirethe use thereof on sensitive skin, owing to odor-inducing factors.

Accordingly, since the requirement to control the odor of thehydrocarbon resin used for sanitary products is increasing with anincrease in the standard of living of consumers, there is an urgent needto develop techniques for reducing the odor of the hydrocarbon resin.

In this regard, U.S. Pat. No. 5,652,308 discloses a tackifier resin inwhich a C3 monomer, propylene, and dicyclopentadiene (DCPD) obtainedfrom a C5 monomer, are copolymerized using a metallocene catalyst,whereby a portion of the C5 monomer is substituted with the C3 monomer.However, when a hydrocarbon resin is prepared using the above method, anexpensive metallocene catalyst, which is very vulnerable to oxygen andwater, has to be used, thus causing problems of complicated processdesigns, high manufacturing costs and a very low yield of less than 30%,making it difficult to achieve real-world application thereof.

Also, the use of a C3 oil fraction, which is in a gas phase, requires anadditional process and apparatus for the liquefaction thereof, andadditional investment costs related to high-pressure reactors may beincurred, and real-world application thereof becomes difficult unlessthe high-pressure reactor is provided.

Moreover, Korean Patent Application No. 2013-0111233 discloses a methodof preparing a hydrocarbon resin using propylene (C3 oil fraction) as anolefin, but problems such as low yield and strong odor may still occur.

DISCLOSURE Technical Problem

Accordingly, the present invention is intended to provide a hydrocarbonresin, a method of preparing the same, and an adhesive compositionincluding the same, in which material supply problems with hydrocarbonresin may be solved, and moreover, a preparation process and yield ofthe hydrocarbon resin that enable real-world application thereof may beensured, and furthermore, odor problems may be alleviated.

Technical Solution

Therefore, the present invention provides a method of preparing ahydrocarbon resin, comprising: (S1) preparing a mixture by mixing adiolefin, a polymerization controller and an initiator; (S2) preparing apolymer by polymerizing the mixture of S1 through the addition of aC2-C20 olefin and a cation catalyst; and (S3) hydrogenating the polymerof S2 through the addition of a hydrogenation catalyst.

Here, the olefin is preferably a C6-C20 olefin, and more preferably aC6-C12 olefin.

In S1, the diolefin may be at least one selected from the groupconsisting of dicyclopentadiene, piperylene, butadiene and propadiene,and dicyclopentadiene is more preferably used.

In S1, the polymerization controller may be at least one selected fromthe group consisting of tricyclodecene, bicyclodecene, 2-methyl-2-buteneand 2-methyl-1-butene.

In S1, the initiator may be at least one selected from the groupconsisting of tert-butyl chloride (t-BuCl, (CH₃)₃CCl), hydrochloric acid(HCl), tert-chlorobutane (t-CH₃(CH₂)₃Cl) and chlorocyclohexane.

In S1, the diolefin, the polymerization controller and the initiator maybe mixed at a molar ratio of 1:0.5˜1.5:0.05˜0.1.

In S2, the cation catalyst may be at least one selected from the groupconsisting of aluminum chloride (AlCl₃), boron trifluoride (BF₃),aluminum bromide (AlBr₃), and silica alumina.

In S2, the olefin may be added in an amount of 0.5˜2.0 mol relative to 1mol of the diolefin.

In S2, the cation catalyst may be added in an amount of 0.001˜0.1 molrelative to 1 mol of the diolefin.

The polymerizing in S2 may be performed at 0˜100° C. for 0.5˜4 hr.

In S3, the hydrogenation catalyst is preferably at least one selectedfrom the group consisting of nickel, palladium, cobalt, platinum andrhodium catalysts, and may be added in an amount of 0.01˜0.5 molrelative to 1 mol of the diolefin. Also, the hydrogenating in S3 may beperformed at a pressure of 50˜150 bar and a temperature of 150˜300° C.

In addition, the present invention provides a hydrocarbon resincomprising a repeating unit represented by Chemical Formula 1 below anda repeating unit represented by Chemical Formula 2 below:

in Chemical Formulas 1 and 2, R₁ is hydrogen or a methyl group and R₂ isa C3-C18 alkyl group.

The hydrocarbon resin of the present invention may have a weight averagemolecular weight of 500˜3000 g/mol, a softening point of 10˜150° C., anda color scale (APHA color) of 1˜100.

In a preferred embodiment of the present invention, the hydrocarbonresin may contain 10˜60 mol % of an olefin-derived component. In anotherpreferred embodiment of the present invention, the hydrocarbon resinincluding a repeating unit represented by Chemical Formula 1 and arepeating unit represented by Chemical Formula 2 may be prepared throughthe aforementioned preparation method.

In addition, the present invention provides an adhesive composition,comprising the hydrocarbon resin including a repeating unit representedby Chemical Formula 1 and a repeating unit represented by ChemicalFormula 2.

Advantageous Effects

According to the present invention, the method of preparing ahydrocarbon resin is capable of solving material supply problems withconventional hydrocarbon resins by replacing a C3 olefin, serving as aconventional hydrocarbon resin material, with a C6-C20 olefin.Furthermore, the C3 olefin essentially needs a liquefaction processbefore polymerization, whereas the use of the C6-C20 olefin according tothe present invention can obviate the liquefaction process.

In particular, a hydrocarbon resin prepared by the method of theinvention is capable of solving unique offensive odor problems withconventional hydrocarbon resins, thereby generating little odor.

Also, the hydrocarbon resin prepared by the method of the invention canexhibit low odor, high adhesion performance, a high softening point,high transparency, a low molecular weight, superior color, and highcompatibility with natural rubber or synthetic rubber, and can thus beusefully employed as a tackifier or an adhesive in a variety of fields.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows the ¹H-NMR spectrum of a polymer before hydrogenation inExample 4 according to the present invention;

FIG. 2 shows the ¹H-NMR spectrum of a hydrocarbon resin afterhydrogenation in Example 4 according to the present invention;

FIG. 3 shows the ¹H-NMR spectrum of a polymer before hydrogenation inComparative Example 3 according to the present invention; and

FIG. 4 shows the ¹H-NMR spectrum of a hydrocarbon resin afterhydrogenation in Comparative Example 3 according to the presentinvention.

BEST MODE

Unless otherwise defined, all the technical and scientific terms usedherein have the same meanings as those typically understood by thoseskilled in the art to which the present invention belongs. Generally,the nomenclature used herein is well known in the art and is typical.

The present invention addresses a method of preparing a hydrocarbonresin, comprising (S1) preparing a mixture by mixing a diolefin, apolymerization controller and an initiator; (S2) preparing a polymer bypolymerizing the mixture of S1 through the addition of a C2-C20 olefinand a cation catalyst; and (S3) hydrogenating the polymer of S2 throughthe addition of a hydrogenation catalyst.

More specifically, according to the present invention, a C6-C20 olefinis used in lieu of a C3 olefin, which is the main material for aconventional hydrocarbon resin, and is copolymerized in the presence ofa cation catalyst, thus yielding a hydrocarbon resin, thereby obviatinga liquefaction process, which is essential before polymerization, andfurthermore, solving material supply problems with hydrocarbon resinowing to the shortage of materials, and ensuring a yield and apreparation process that enable real-world application thereof.

In S2 of the present invention, a C6-C20 olefin is used, thus solvingthe problem in which it is difficult to supply a C5 olefin, serving as amain material for a conventional hydrocarbon resin and obviating theliquefaction process required upon using a C3 olefin, particularlyensuring a yield and a preparation process that enable real-worldapplication thereof. The olefin is preferably a C6-C16 olefin, and morepreferably a C6-C12 olefin.

In the method of the present invention, the C6-C20 olefin and thediolefin are polymerized and then the hydrogenation catalyst is addedthereto to prepare a hydrocarbon resin. Here, the hydrocarbon resin ofthe invention is imparted, through the copolymerization of the olefin,with a molecular structure different from that of a conventionalhydrocarbon resin, whereby the hydrocarbon resin prepared by the methodof the present invention may exhibit a reduced odor compared to theconventional hydrocarbon resin.

In S2, the olefin may have one or at least two double bonds, andpreferably one double bond. More preferably, a linear olefin is used.

Specifically, the olefin may include at least one selected from thegroup consisting of hexene, heptene, octene, nonene, decene anddodecene, and preferably at least one selected from the group consistingof linear α-olefin, such as 1-hexene, 1-heptene, 1-octene, 1-nonene,1-decene and 1-dodecene. Particularly useful is 1-hexene, 1-octene,1-decene or 1-dodecene in order to ensure a desired price and supplythereof.

The diolefin may be at least one selected from the group consisting ofdicyclopentadiene, piperylene, butadiene and propadiene, anddicyclopentadiene is preferably used in order to realize superiorcopolymerization with olefin.

In S1, the polymerization controller may be at least one selected fromthe group consisting of tricyclodecene, bicyclodecene, 2-methyl-2-buteneand 2-methyl-1-butene, and tricyclodecene is preferably used in order tocontrol a molecular weight.

In S1, the initiator may be at least one selected from the groupconsisting of tert-butyl chloride (t-BuCl, (CH₃)₃CCl), hydrochloric acid(HCl), tert-chlorobutane (t-CH₃(CH₂)₃Cl) and chlorocyclohexane. Inparticular, tert-butyl chloride (t-BuCl) is preferably used in order torealize a high yield.

In S1, the diolefin, the polymerization controller and the initiator aremixed at a molar ratio of 1:0.5˜1.5:0.05˜0.1 in order to ensure superiorproperties of the hydrocarbon resin.

The diolefin is dissolved in a solvent before polymerization with theolefin, followed by polymerization with the olefin, resulting in ahydrocarbon resin. Here, the solvent may be used without limitation solong as it is able to dissolve the diolefin. Preferably, toluene,methylene chloride, hexane, xylene, trichlorobenzene, alkyl benzene orthe like is used.

The amount of the solvent is not particularly limited so long as it isable to sufficiently dissolve diolefin and olefin, and may be 2˜10 molrelative to 1 mol of the diolefin.

The polymerization is carried out at 0˜100° C. for 0.5˜4 hr. If thepolymerization is performed under conditions of a temperature less than0° C. or a time less than 0.5 hr, a low yield may result. On the otherhand, if the polymerization is performed under conditions of atemperature exceeding 100° C. or a time exceeding 4 hr, a gel may beformed.

Useful in the polymerization, the cation catalyst may be used withoutlimitation so long as it is able to polymerize the olefin and thediolefin, and is preferably at least one selected from the groupconsisting of aluminum chloride (AlCl₃), boron trifluoride (BF₃),aluminum bromide (AlBr₃), and silica alumina, and AlCl₃ is morepreferably used in order to ensure superior properties of thehydrocarbon resin.

The cation catalyst is preferably used in an amount of 0.001˜0.1 molrelative to 1 mol of the diolefin. If the amount thereof is less than0.001 mol relative to 1 mol of the diolefin, insufficient reactionactivity may result. On the other hand, if the amount thereof exceeds0.1 mol, the removal of the catalyst is not easy, and economic benefitsmay be negated due to the use of a large amount of catalyst.

In S3, the hydrogenation catalyst may be selected from the groupconsisting of nickel, palladium, cobalt, platinum and rhodium catalysts.The use of palladium (Pd) is more preferable in order to improvehydrogenation reactivity.

The hydrogenation catalyst is preferably used in an amount of 0.01˜0.5mol relative to 1 mol of the diolefin. If the amount thereof is lessthan 0.01 mol relative to 1 mol of the diolefin, reactivity maydecrease. On the other hand, if the amount thereof exceeds 0.5 mol,economic benefits may be negated due to the use of a large amount ofcatalyst.

The hydrogenation in S3 may be carried out at a pressure of 50˜150 barand a temperature of 150˜300° C. If the reaction is carried out at apressure exceeding 150 bar or a temperature higher than 300° C., themolecular structure may break down under the harsh reaction conditions.On the other hand, if the reaction pressure or temperature is less than50 bar or 150° C. respectively, hydrogenation may not be sufficientlycarried out.

The preparation method according to the present invention enables thepreparation of a hydrogenated hydrocarbon resin at a high yield(conversion) of 30% or more by polymerizing the olefin and the diolefin.In the method of the present invention, the C6-C12 olefin in a liquidphase is used, whereby liquid-liquid polymerization may be carried outwith high reactivity compared to gas-liquid polymerization, and thetemperature for the polymerization reaction may be elevated to 40° C. ormore, thereby further increasing the preparation yield.

Particularly in the present invention, a portion of a C5 diolefin, theshortage of which is becoming severe among materials for a hydrocarbonresin, may be replaced with a C6-C20 olefin, thereby solving the problemin which the supply of hydrocarbon resin material is insufficient.

In addition, the present invention addresses a hydrocarbon resinincluding a repeating unit represented by Chemical Formula 1 below and arepeating unit represented by Chemical Formula 2 below.

In Chemical Formulas 1 and 2, R₁ is hydrogen or a methyl group and R₂ isa C3-C18 alkyl group.

The hydrocarbon resin of the present invention is configured such thatno double bond remains in the cyclic structure thereof and the odor isreduced by polymerizing a C6-C20 olefin, which substitutes for a portionof dicyclopentadiene, which has a strong odor. Hydrogenation isconducted so that no double bond remains, as represented by ChemicalFormulas 1 and 2, and also, the odor of the hydrocarbon resin may bereduced by polymerizing the C6-C20 olefin.

Also, the hydrocarbon resin of the present invention may increasecompatibility with various polymers by virtue of olefin polymerization,thus enhancing adhesion and cohesion.

The hydrocarbon resin of the present invention has a weight averagemolecular weight of 500˜3,000 g/mol, a softening point of 10˜150° C.,and a color scale (APHA color) of 1˜100. If the weight average molecularweight thereof is less than 500 g/mol, adhesion may deteriorate. On theother hand, if the weight average molecular weight thereof exceeds 3000g/mol, compatibility may decrease. If the softening point thereof isless than 10° C., adhesion may deteriorate. On the other hand, if thesoftening point thereof is higher than 150° C., it is difficult toperform the preparation process.

If the color scale (APHA color) exceeds 100, a poor color may result,which is considered a defect upon the preparation of an adhesive.

The hydrocarbon resin of the present invention may contain 10˜60 mol %of an olefin-derived component. If the amount of the olefin is less than10 mol %, it is difficult to exhibit olefin copolymerization properties.On the other hand, if the amount thereof exceeds 60 mol %, adhesionperformance may deteriorate.

The hydrocarbon resin prepared according to the present invention isable to impart tackiness and adhesiveness to a hot-melt adhesive, apressure-sensitive adhesive, ink, paint, road-marking paint, and thelike, and may be blended with various resins, such as natural rubber,synthetic rubber and the like, and may thus be usefully employed as anadhesive or a tackifier.

MODE FOR INVENTION

A better understanding of the present invention may be obtained throughthe following examples, which are set forth to illustrate, but are notto be construed as limiting the scope of the present invention.

EXAMPLES Example 1

In a 1 L autoclave, dicyclopentadiene (DCPD) was dissolved in 500 ml ofa toluene solvent, and a polymerization controller, tricyclodecene(TCDE), was then added thereto. Also, an initiator, t-BuCl, was addedthereto, and the reactor was closed, after which an olefin was addedthereto, and the resulting mixture was added with a catalyst and thenallowed to react. The reaction temperature was maintained at 40° C. andthe reaction was terminated after 2 hr. After completion of thereaction, the produced polymer was mixed with 300 g of water to separatethe catalyst, and was then distilled at 200° C. for 5 min to recoverunreacted oil fractions, thus obtaining 300 g of the remaining polymer.

The 300 g of the polymer thus obtained was added with a hydrogenationsolvent, toluene, in an amount 1.5 times the amount of the polymer,which was thus completely dissolved, and was then placed in a 1 Lautoclave. Thereafter, 60 g of a palladium catalyst was added thereto,and the reactor was closed, after which a hydrogenation reaction wascarried out at a hydrogen pressure of 80 bar and a temperature of 230°C. for 90 min. After termination of the reaction, the produced reactionliquid was distilled in a vacuum of 5 torr at 250° C. for 5 min, therebyyielding 150 g of a hydrogenated hydrocarbon resin (a yield of 41%). Thekinds and amounts of individual components of the hydrocarbon resin aregiven in Table 1 below.

Examples 2 to 7

The hydrocarbon resins of Examples 2 to 7 were prepared in the samemanner as in Example 1 under the conditions shown in Table 1 below.

The ¹H-NMR spectrum results of the polymer before hydrogenation and thehydrocarbon resin after hydrogenation in Example 4, measured using anNMR spectrometer (500 NMR made by Bruker, 14.1 tesla), are shown inFIGS. 1 and 2, respectively. Based on the ¹H-NMR spectrum results ofFIGS. 1 and 2, the polymer before hydrogenation and the hydrocarbonresin after hydrogenation were confirmed to be polymerized.

Comparative Example 1

In a 1 L autoclave, dicyclopentadiene (DCPD) was dissolved in 500 ml ofa toluene solvent, and a polymerization controller, tricyclodecene(TCDE), was then added thereto. Also, an initiator, t-BuCl, was addedthereto, DCPD and piperylene were added thereto, and the reactor wasclosed, after which the resulting mixture was added with 0.038 mol of acatalyst BF₃ and then allowed to react. The reaction temperature wasmaintained at 40° C. and the reaction was terminated after 2 hr. Aftercompletion of the reaction, the produced polymer was mixed with 300 g ofwater to separate the catalyst, and was then distilled at 200° C. for 5min to recover unreacted oil fractions, thus obtaining 300 g of theremaining polymer.

The 300 g of the polymer thus obtained was added with a hydrogenationsolvent, toluene, in an amount 1.5 times the amount of the polymer,which was thus completely dissolved, and was then placed in a 1 Lautoclave. Thereafter, 60 g of a palladium catalyst was added thereto,and the reactor was closed, after which a hydrogenation reaction wascarried out at a hydrogen pressure of 80 bar and a temperature of 230°C. for 90 min. After termination of the reaction, the produced reactionliquid was distilled in a vacuum of 5 torr at 250° C. for 5 min, therebyyielding 175 g of a hydrogenated hydrocarbon resin (a yield of 56%). Thekinds and amounts of individual components are given in Table 1 below.

Comparative Examples 2 to 8

The hydrocarbon resins of Comparative Examples 2 to 8 were prepared inthe same manner as in Example 1 under the conditions shown in Table 1below.

The ¹H-NMR spectrum results of the polymer before hydrogenation and thehydrocarbon resin after hydrogenation in Comparative Example 3, measuredusing an NMR spectrometer (500 NMR made by Bruker, 14.1 tesla), areshown in FIGS. 3 and 4, respectively. Based on the ¹H-NMR spectrumresults of FIGS. 3 and 4, the polymer before hydrogenation and thehydrocarbon resin after hydrogenation were confirmed to be polymerized.

TABLE 1 Polymeri- Hydro- zation genation conditions conditions Material(mol) Polymeri- Hydro- (S2) (S3) Olefin zation Ini- Cation genation Tem-Tem- Diolefin 1- 1- 1- 1- 1- controller tiator catalyst catalyst pera-pera- Pres- Piper- pro- hex- oc- de- dode- (mol) (mol) (mol) (mol) (mol)ture Time ture sure No. DCPD ylene pene ene tene cene cene TCDE t-BuClBF₃ AlCl₃ Pd (° C.) (hr) (° C.) bar Ex. 1 1.06 — — 1.06 — — — 1.06 0.0750.038 — 0.2 40 2 230 80 Ex. 2 0.8 — — 1.6  — — — 0.8 0.075 0.038 — 0.240 2 230 80 Ex. 3 0.8 — — 1.6  — — — 0.8 0.075 — 0.038 0.2 40 2 230 80Ex. 4 0.8 — — — 1.6 — — 0.8 0.075 0.038 — 0.2 40 2 230 80 Ex. 5 0.8 — —— 1.6 — — 0.8 0.075 — 0.038 0.2 40 2 230 80 Ex. 6 0.8 — — — — 1.6  — 0.80.075 — 0.38 0.2 40 2 230 80 Ex. 7 0.8 — — — — 1.6  0.8 0.075 — 0.38 0.240 2 230 80 Ex. 8 0.8 1,6 0.8 0.075 — 0.38 0.2 40 2 230 80 (β- octene)C. Ex. 1 1.06 1.06 — — — — — 1.06 — — 0.038 0.2 30 2 230 80 C. Ex. 2 —1.6  — — — — — 1.6 — — 0.038 0.2 30 2 230 80 C. Ex. 3 1.6 — — — — — —1.6 — 0.038 0.2 40 2 230 80 C. Ex. 4 1.06 — 1.06 — — — — 1.06 0.075 —0.038 0.2 40 2 230 80 C. Ex. 5 1.06 — — 1.06 — — — 1.06 0.075 — 0.038 —40 2 C. Ex. 6 1.06 — — —  1.06 — — 1.06 0.075 — 0.038 — 40 2 C. Ex. 71.06 — — — — 1.06 — 1.06 0.075 0.038 — 40 2 C. Ex. 8 1.06 — — — — — 1.061.06 0.075 0.038 — 40 2

<Evaluation of Properties>

(1) Yield

The yield was determined as follows.

Yield (%)=obtained resin (g)/total of added monomers (g) 100

(2) Softening Point

A softening point was measured using a ring-and-ball softening method(ASTM E 28). The resin was dissolved and placed in a ring-shaped mold,which was then hung on a beaker containing glycerin, after which a ballwas placed on the resin-containing ring and the temperature was elevatedat a rate of 2.5° C./min to reach the temperature at which the resin wasdissolved, and the temperature (softening point) at which the ball fellwas measured. The results are shown in Table 3 below.

(3) Molecular Weight

Through gel permeation chromatography (GPC) (PL GPC-220) using apolystyrene standard, a weight average molecular weight, a numberaverage molecular weight and a z-average molecular weight were measured.The hydrogenated hydrocarbon resin to be measured was dissolved in1,2,4-trichlorobenzene so as to have a concentration of 0.34 wt %, and288 μL thereof was introduced into GPC. The mobile phase of GPC was1,2,4-trichlorobenzene, and was introduced at a flow rate of 1 mL/min,and analysis was conducted at 130° C. Two guard columns and one PL 5 μmmixed-D column were connected in series. Measurement was performed byelevating the temperature to 250° C. at a rate of 10° C./min using adifferential scanning calorimeter, and analysis was conducted in an N₂atmosphere up to the 2nd scan. The results are shown in Table 3 below.

In Table 3, Mn indicates the number average molecular weight, Mwindicates the weight average molecular weight, Mz indicates thez-average molecular weight, and PD (polydispersity) indicates Mw/Mn.

(4) Olefin Content in Resin

The olefin content (mol %) in the polymer was analyzed based on ¹H-NMRspectrum results using an NMR spectrometer (500 NMR made by Bruker, 14.1tesla).

(5) Color (APHA)

Color was measured in accordance with ASTM D1544. Specifically, 10.0 gof the hydrogenated hydrocarbon resin was dissolved in 10.0 g of tolueneand was then placed in a quartz cell having a rectangular cross-section(a width of 5 cm, a length of 4 cm and a path length of 50 mm). Thiscell was mounted to a PFX195 colorimeter and operated to measure an APHAcolor.

(6) Specific Gravity

A specific gravity was measured in accordance with ASTM D71.Specifically, 5 g of the hydrogenated hydrocarbon resin was dissolved ona hot plate at 200° C. and poured into a sphere-shaped mold, and thecured hydrogenated hydrocarbon resin having a sphere shape was removedfrom the mold and then placed in a densimeter (QUALITEST: DensimeterSD-200L) to measure the specific gravity thereof.

(7) Odor Intensity

The odor intensity of the hydrocarbon resin was evaluated using a panelcomprising five male and female participants. 10 g of the hydrocarbonresin was placed in a 100 ml beaker, which was then placed in an oven at180° C. for 30 min. The beaker in a hot state was taken out of the ovenand the odor generated from the hydrocarbon resin was evaluated. Theodor intensity was evaluated in a manner in which the participantssmelled the odor, and the results thereof were classified into numericalvalues according to the classification table of Table 2 below, afterwhich a score from 0 to 5 was assigned and the average score wascalculated.

TABLE 2 Odor Score intensity Description 0 None Relatively odorlesslevel and state in which no smell is detected 1 Threshold State of notbeing able to identify the smell but being able to sense the smell 2Moderate State of being able to identify the smell 3 Strong Strong smellthat is easy to detect (state of being able to detect the unique smellof cresol in hospital) 4 Very Very strong smell (severe condition instrong conventional toilet) 5 Over Extremely strong smell that is hardto withstand strong to the extent of feeling interference with breathing

<Results of Evaluation of Properties of Resin>

The results measured as above are shown in Table 3 below.

TABLE 3 Softening Olefin content Yield point Molecular weight in resinColor Specific No. (%) (° C.) Mn Mw Mz PD (mol %) APHA gravity Odor Ex.1 41 110 417 1569 8104 3.76 42 20 1.03 1.6 Ex. 2 39 91 502 1400 95212.79 51 30 1.03 1.4 Ex. 3 50 95 682 1651 10101 2.42 55 20 1.03 1.2 Ex. 448 95 515 1398 9132 2.71 50 20 1.04 1.2 Ex. 5 52 97 695 1752 9548 2.5249 20 1.03 1.0 Ex. 6 50 100 701 1871 9582 2.67 40 20 1.03 0.9 Ex. 7 53101 721 1825 10902 2.53 38 20 1.03 0.9 Ex. 8 49 109 550 1685 8624 3.0630 20 1.04 1.2 C. Ex. 1 56 85 861 2875 11323 3.34 35 25 1.05 2.9 C. Ex.2 61 90 627 2100 9321 3.34 0 20 1.05 2.7 C. Ex. 3 55 120 303 733 55422.41 0 20 1.08 3.2 C. Ex. 4 30 80 303 654 3452 2.16 30 20 1.05 4.5 C.Ex. 5 40 105 405 1520 8050 3.75 42 500 or more 1.08 4.2 C. Ex. 6 46 90504 1299 8682 2.57 50 500 or more 1.08 4.0 C. Ex. 7 49 98 698 1851 95202.65 40 500 or more 1.07 3.9 C. Ex. 8 51 99 705 1859 10885 2.64 38 500or more 1.07 3.9

As is apparent from Table 3, Examples 1 to 7 exhibited slightly lowyield compared to Comparative Examples 1 to 3, but had equivalent yield.

The color scale of the hydrocarbon resin of Examples was 20 or more,which means that the hydrocarbon resin of the invention is suitable foruse by being mixed with other resins.

Moreover, the hydrocarbon resin of Examples manifested significantlyreduced odor compared to Comparative Examples.

In particular, in Comparative Example 4, pertaining to the preparationof a hydrocarbon resin using propylene as disclosed in Korean PatentApplication No. 2013-0111233, a remarkably lowered yield, a highspecific gravity and a considerably high odor resulted.

Therefore, the method of preparing the hydrocarbon resin according tothe present invention is able to replace the C3 monomer, which is aconventional hydrocarbon resin material, with the other material, thussolving material supply problems, and also ensuring a preparationprocess and a yield that enable real-world application thereof, bypreparing the hydrocarbon resin using a catalyst that is inexpensive andis easy to handle.

Although specific embodiments of the present invention have beendisclosed in detail as described above, it is obvious to those skilledin the art that such description is merely of preferable exemplaryembodiments and is not to be construed to limit the scope of the presentinvention. Therefore, the substantial scope of the present inventionwill be defined by the appended claims and equivalents thereof.

1. A method of preparing a hydrocarbon resin, comprising: (S1) preparinga mixture by mixing a diolefin, a polymerization controller and aninitiator; (S2) preparing a polymer by copolymerizing the mixture of S1through addition of a C6-C20 olefin and a cation catalyst; and (S3)hydrogenating the polymer of S2 through addition of a hydrogenationcatalyst.
 2. The method of claim 1, wherein the diolefin in S1 is atleast one selected from the group consisting of dicyclopentadiene,piperylene, butadiene and propadiene.
 3. The method of claim 1, whereinthe polymerization controller in S1 is at least one selected from thegroup consisting of tricyclodecene, bicyclodecene, 2-methyl-2-butene and2-methyl-1-butene.
 4. The method of claim 1, wherein the initiator in S1is at least one selected from the group consisting of tert-butylchloride (t-BuCl, (CH₃)₃CCl), hydrochloric acid (HCl), n-butyl chloride(t-CH₃(CH₂)₃Cl) and chlorocyclohexane.
 5. The method of claim 1, whereinthe diolefin, the polymerization controller and the initiator in S1 aremixed at a molar ratio of 1:0.5˜1.5:0.05˜0.1.
 6. The method of claim 1,wherein the cation catalyst in S2 is at least one selected from thegroup consisting of aluminum chloride (AlCl₃), boron trifluoride (BF₃),aluminum bromide (AlBr₃), and silica alumina.
 7. The method of claim 1,wherein the olefin in S2 is added in an amount of 0.5 to 2.0 molrelative to 1 mol of the diolefin.
 8. The method of claim 1, wherein thecation catalyst in S2 is added in an amount of 0.001 to 0.1 mol relativeto 1 mol of the diolefin.
 9. The method of claim 1, wherein S2 isperformed at 0˜100° C. for 0.5˜4 hr.
 10. The method of claim 1, whereinthe hydrogenation catalyst in S3 is at least one selected from the groupconsisting of nickel, palladium, cobalt, platinum and rhodium catalysts.11. The method of claim 1, wherein the hydrogenation catalyst in S3 isadded in an amount of 0.01 to 0.5 mol relative to 1 mol of the diolefin.12. The method of claim 1, wherein the hydrogenating in S3 is performedat a pressure of 50˜150 bar and a temperature of 150˜300° C.
 13. Ahydrocarbon resin, comprising a repeating unit represented by ChemicalFormula 1 below and a repeating unit represented by Chemical Formula 2below:

in Chemical Formulas 1 and 2, R₁ is hydrogen or a methyl group and R₂ isa C3-C18 alkyl group.
 14. The hydrocarbon resin of claim 13, wherein thehydrocarbon resin has a weight average molecular weight of 500˜3000g/mol, a softening point of 10˜150° C., and a color scale (APHA color)of 1˜100.
 15. The hydrocarbon resin of claim 13, wherein the hydrocarbonresin contains 10˜60 mol % of an olefin-derived component.
 16. Thehydrocarbon resin of claim 13, wherein the hydrocarbon resin is preparedby the method of claim
 1. 17. An adhesive composition comprising thehydrocarbon resin of claim 13.